Universal couplings and chains incorporating such couplings

ABSTRACT

A universal coupling suitable for connecting chain links of the kind fabricated from metal strip, the coupling comprises two interconnected looped members which are located in planes normal to one another, and each of which has a curved end extending through the curved end of the other member, and a pivot block, trapped between the said curved ends, has two opposed convex surfaces each of which is concentric to an axis normal to the axis of the other surface and contacts the adjacent curved link end so that the axis of the block surface and the axis of the said adjacent link end are in parallel.

United States Patent [191 Miburn-Bathgate 1 1 UNIVERSAL COUPLINGS ANDCHAINS INCORPORATING SUCH COUPLINGS [75] Inventor: CharlesMiburn-Bathgate, West Hagley, England [73] Assignee: Cavamatic Limited,Bridgnorth,

Shropshire, England [22] Filed: Apr. 2, 1971 [21] Appl. No.: 130,637

[ 1 Aug. 21, 1973 916,288 1/1963 Great Britain 59/84 PrimaryExaminer-Evon C. Blunk Assistant Examiner-Douglas D. WattsAttorney-Imirie & Smiley [57] ABSTRACT A universal coupling suitable forconnecting chain links of the kind fabricated from metal strip, thecoupling comprises two interconnected looped members which are locatedin planes normal to one another, and each of which has a curved endextending through the curved end of the other member, and a pivot block,trapped between the said curved ends, has two opposed convex surfaceseach of which is concentric to an axis normal to the axis of the othersurface and contacts the adjacent curved link end so that the axis ofthe block surface and the axis of the said adjacent link end are inparallel.

4 Claims, 6 Drawing Figures PATENTEDAUBZI I873 sum e er 2 INVENTORCHARLEs MiLsoR N- BATH GATE ICU/.5.

UNIVERSAL COUPLINGS AND CHAINS INCORPORATING SUCH COUPLINGS Thisinvention relates to universal couplings of the kind comprising twolooped members each of which extends through the interior of the other,and to chains, particularly conveyor chains, wherein the links areinterconnected by and form parts of the couplings.

In accordance with one aspect of the invention, a universal couplingcomprises two looped members which are located in planes normal to oneanother, each looped member has a curved end which is concentric to anaxis normal to the plane of the member and extends through the curvedend of the other member, and a pivot block having two opposed convexsurfaces each of which is concentric to an axis normal to the axis ofthe other surface, is trapped between the curved ends of the two loopedmembers with each convex surface in contact with the adjacent curved endand with the axes of each contacting surface and end in parallel.

Preferably the radii of the curved ends of the looped members and of theconvex block surfaces are equal, each of the curved ends is locatedbetween two lips projecting from the adjacent curved block surface, andthe maximum distance between the two convex surfaces is less than thelength of the said radii.

In accordance with another aspect of the invention each link of a chainis fabricated from a flat strip of which the plane is normal to theplane of the link, the adjacent curved ends of each two interconnectedlinks of chain form the looped members of one of the universalcouplings, and one of the pivot blocks is trapped between the saidadjacent curved ends to complete the coupling.

In accordance with a further aspect of the invention, the chain isaccommodated in and extends lengthwise of a tubular conveyor track whichis rectangular in cross section, each link of the chain has a centrallongitudinal portion of which the width is less than the maximum widthof the curved ends of the link, the central portion is flanked by a pairof wheels which the diameter exceeds the width of the strip, the wheelsare rotatable about the axis of a spindle extending through the centralportion transversely of the link, and the peripheries of the wheels makerolling contact with the internal surfaces of two opposed walls of thetrack.

In order that the invention may be understood and carried into practicemore readily, reference will now be made to the accompanying drawingswherein:

FIG. 1 is an elevation of part of an overhead conveyor comprising atubular track of which one half has been removed and one of the links ofa chain accommodated within the track has been partly broken away.

FIG. 2 is a section along the line a-a, FIG. 1, in which another one ofthe chain links has been partly broken away.

FIG. 3 is a section along the line b-b, FIG. 1.

FIG. 4 and 5 are, respectively, enlarged scale sections along the linec-c, FIG. 1, and d-d, FIG. 2, and

FIG. 6 is perspective view, on a still larger scale, of one of the pivotblocks provided in the chain.

The overhead conveyor shown in FIGS. 1 and 2 comprises a fixed, tubulartrack I which is square in cross section, and a chain 2 which isaccommodated within and extends along the length of the track.

Each link 3 of the chain is fabricated from a flat metal strip of whichthe plane is normal to the plane of the link; each end 4 of the link issemi-circular, of the same radius as the other end and its externalsurface is convex; each side of the link has a straight central portion5 which is parallel to and of the same length as, the central portion ofthe opposite side, and the two straight portions are spaced apart by adistance less than the radius of the semi-circular ends; each twocorresponding ends of the central portions are united to the adjacentsemi-circular end by straight, diverging portions 6 of the strip, andthe opposite ends of the strip overlap and are secured to one another inone of the central portions 5.

Each chain link is provided with a spindle 7 which extends through apair of registering holes pierced, respectively, in the two centralstraight portions of the link sides, and a corresponding one of a pairof wheels 8 is mounted upon each end of the spindle externally of thelink. A washer 9 is mounted around the spindle externally of the linkside opposite to the overlapping strip ends and between the said linkside and the corresponding wheel. The wheels are carried upon rollerbearings of which the inner races 10 are fixed to the spindle.

Each two adjoining links of the chain are located in planes which arenormal to one another, one curved end of each link extends through theadjacent curved end of the adjoining link so that the two links areinter connected and a pivot block 11 which, for example, may be astamping, pressing or moulding composed of a low-friction, bearingmaterial, is located and trapped between the internal surfaces of theadjacent curved link ends.

The opposed surfaces 12, 13 of the pivot block are convex and each isconcentric to an axis which is normal to the axis of the other convexsurface; the radius of each of the convex surfaces is equal to theradius of the internal concave surfaces of the curved link ends but isgreater than the maximum distance between the said surfaces; each of theconvex surfaces is flanked by two flat and parallel block portions 14each having a lip 15 which projects beyond the corresponding convexsurface; the lips projecting beyond each convex surface are spaced apartby a distance which is equal to the distance between the lips projectingbeyond the other convex surface but is not less than the width of thestrip from which the chain links are fabricated. Further, although thecurved link ends are semicircular and, consequently, span angles of theconvex block surfaces span angles of less than 180.

Each of the pivot blocks is so located between the concave surfaces ofthe curved link ends between which it is trapped, that the axis of eachconvex block surface is parallel to the axis of the adjacent link end.Hence, when the chain is tensioned, the convex surfaces of each pivotblock respectively abut against, nest within, and make rolling contactwith the internal surfaces of the link ends between which the block istrapped, each of the link ends is located between a corresponding two ofthe lips 15, and the two interconnected link ends are adapted to swingrelatively to one another about the axis of either of the convex blocksurfaces. Consequently, each two interconnected link ends and the pivotblock trapped therebetween, are adapted to function as a universalcoupling so that the chain, when driven along the interior of the track,is able to travel easily and smoothly, in any direction around smallradius bends in the track.

The internal surfaces of each two opposed and parallel walls of thetrack 1 are spaced apart by a distance equal to the diameter of thewheels 8 so that the peripheries of the two wheels mounted upon eachspindle 7 make rolling contact with the internal surfaces of acorresponding opposed two of the track walls, one of the said walls isformed with a central longitudinal slot 16 whereas the wall opposite tothe slotted wall is provided with an external, longitudinal flange 17 sothat the track may be secured to any desired means of support.

The spindle 7 extending through each of the alternate links of which theplane is parallel to the slotted track wall, has one end of a bar 18mounted freely around it between the straight parallel side portions ofthe link, and the said bar depends freely through the slot 16 to theexterior of the track so that a load may be suspended therefrom. In eachof the other links, the bar 18 is replaced by a spacing bush 19 of whichthe length is equal to the thickness of the bar.

Although the invention has been described with specific reference to thechain of a conveyor, it is apparent that the block 11 is capable ofbeing inserted and trapped between curved ends of any two loopedmembers, other than chain links, to provide a universal coupling whichenables the member to be swung relatively to one another about the axisof eitherof the convex block surfaces 12, 13 thereby simplifying theconstruction and minimising the production costs of the coupling.

I claim:

1. A conveyor comprising a track and a chain extending lengthwise ofsaid track, said track having a transverse wall extending between sidewalls with a longitudinally extending slot in its transverse wall, saidchain including a plurality of links, each said link comprising a loopedmember fabricated from flat strip of which the plane is normal to theplane of said link and adjacent ones of said looped members beinglocated in planes normal to one another, the planes of alternate linksbeing parallel with said track transverse wall, each said looped memberhaving a pair of curved ends which respectively are concentric to anaxis normal to the plane of the member with the ends of said stripoverlapping midway between said curved ends, a curved end of one saidlooped member extending through and linked with a curved end of anadjacent said looped member, a pivot block trapped between each pair oflinked curved ends; said pivot block having two opposed convex surfaces,one of said convex surfaces being concentric to an axis normal to theaxis of the other of said convex surfaces, each said convex surfacebeing concentric with and engaging the adjacent one of said curved ends,said axis of each said convex surface and said curved ends beingparallel, the overlapping ends and medium portion of said stripsconstituting the alternate links parallel with said track bottom walleach having aligned bores transversely of each said looped member midwaybetween said curved ends, a spindle extending through each said bores, apair of wheels mounted on opposite ends of each said spindle andengaging with said track transverse wall on opposite sides of said slot,and a bar mounted at one end on each said shaft and depending throughsaid slot for conveying a load along said track.

2. A conveyor according to claim 1 wherein the central portion of eachsaid looped member through which a spindle extends has a width less thanthe maximum width of said curved ends.

3. A conveyor according to claim 1 wherein the radius of each saidconvex surface is equal to the radius of the inner side of said adjacentcurved end to constitute a cylindrical bearing, and said pivot block hastwo lips projecting radially from the opposite sides of each said convexsurface of said pivot block, and said adjacent linked curved end isnested between said lips to preclude deviation from said axis.

4. A conveyor according to claim 1 wherein the overlapping ends andmedium portion of said strips constituting the links intermediate saidalternate links and which are parallel with the track side walls eachhaving aligned bores transversely of each said looped member midwaybetween said curved ends, a shaft extending through each said bores, apair of wheels mounted on opposite ends of each said shaft and engagablewith said track side walls to assist in maintaining said links inalignment.

UNITED STATES PATENT GF-FECE ETIMQATE i QGRRECTEON Patent 3,753,487Dated August 21, 1973 Inventor) Charles MILBURN-BATHGATE It is certifiedthat error appears in the above-identified patent and that said LettersPatent are hereby corrected as shown below:

Inventor's name should read: -Char1es MILBURN-BATHGATE Signed and sealedthis 20th day of November 1973.

(SEAL) Attest:

EDWARD M.FLETCHER,JR. RENE D. TEGTMEYER Attesting Officer ActingCommissioner of Patents F ORM PO-105O (10-69) USCOMM-DC 60376-P69 J25.u.s. sovznnmsu-r PRINTING OFFICE: was o-sss-au \f'

1. A conveyor comprising a track and a chain extending lengthwise ofsaid track, said track having a transverse wall extending between sidewalls with a longitudinally extending slot in its transverse wall, saidchain including a plurality of links, each said link comprising a loopedmember fabricated from flat strip of which the plane is normal to theplane of said link and adjacent ones of said looped members beinglocated in planes normal to one another, the planes of alternate linksbeing parallel with said track transverse wall, each said looped memberhaving a pair of curved ends which respectively are concentric to anaxis normal to the plane of the member with the ends of said stripoverlapping midway between said curved ends, a curved end of one saidlooped member extending through and linked with a curved end of anadjacent said looped member, a pivot block trapped between each pair oflinked curved ends; said pivot block having two opposed convex surfaces,one of said convex surfaces being concentric to an axis normal to theaxis of the other of said convex surfaces, each said convex surfacebeing concentric with and engaging the adjacent one of said curved ends,said axis of each said convex surface and said curved ends beingparallel, the overlapping ends and medium portion of said stripsconstituting the alternate links parallel with said track bottom walleach having aligned bores transversely of each said looped member midwaybetween said curved ends, a spindle extending through each said bores, apair of wheels mounted on opposite ends of each said spindle andengaging with said track transverse wall on opposite sides of said slot,and a bar mounted at one end on each said shaft and depending throughsaid slot for conveying a load along said track.
 2. A conveyor accordingto claim 1 wherein the central portion of each said looped memberthrough which a spindle extends has a width less than the maximum widthof said curved ends.
 3. A conveyor according to claim 1 wherein theradius of each said convex surface is equal to the radius of the innerside of said adjacent curved end to constitute a cylindrical bearing,and said pivot block has two lips projecting radially from the oppositesides of each said convex surface of said pivot block, and said adjacentlinked curved end is nested between said lips to preclude deviation fromsaid axis.
 4. A conveyor according to claim 1 wherein the overlappingends and medium portion of said strips constituting the linksintermeDiate said alternate links and which are parallel with the trackside walls each having aligned bores transversely of each said loopedmember midway between said curved ends, a shaft extending through eachsaid bores, a pair of wheels mounted on opposite ends of each said shaftand engagable with said track side walls to assist in maintaining saidlinks in alignment.